An international law expert says it is highly unlikely that the American man Gabe Watson will face a murder trial in the United States.

Watson is serving 18 months in jail for the manslaughter of his wife Tina Watson who drowned during a honeymoon scuba-diving trip in north Queensland in 2003.

Ms Watson's family is lobbying the US Government to charge Gabe Watson with murder upon his return, and to try him in Alabama.

The University of Queensland's Professor Andreas Schloenhardt says that would be hindered by double jeopardy laws and extradition issues because of the death penalty.

"I think that the chances of this going to trial in Alabama are very slim," he said.

"It seems that there's a lot of publicity involved in the recent statements both by the victim's family and by the authorities over there.

"I think the chances of him really being sent to the United States at any time are highly unlikely."

Tina Watson's mother Cindy Thomas has told Fairfax radio the Queensland Government is not helping.

"I think they're just not cooperating in the way that they should," Mrs Thomas said.

The Attorney General's office says it has no record of a request for the complete Gabe Watson file from the Alabama Attorney-General in the US.

The State Opposition leader says the Attorney General should be doing everything in his power to help US authorities.

Opposition leader John Paul Langbroek says the Attorney General is not doing enough to help U-S authorities.

"If the Attorney General promised that information would be provided then that information should be provided and it's not a matter of the Attorney General fobbing it off to the DPP or to the police service," he said.

You have no doubt been hearing a lot about the Paris Agreement and know that it pertains to climate change, but are too embarrassed at this stage to ask for an overall explanation of what it's all about.